1. Field of the Invention
The present invention is related to shaft furnaces and, more particularly, to a probe for use in obtaining gas samples from within a shaft furnace during operation such as a blast furnace.
2. Description of the Prior Art
The present invention is an improvement in apparatus for taking gas samples in shaft furnaces, particularly blast furnaces, as shown and described in U.S. Pat. No. 3,888,123. This patent also refers specifically to U.S. Pat. No. 3,240,069 as one other embodiment of a blast furnace probe.
U.S. Pat. No. 3,888,123 discloses an elongate cylindrical tube comprised of an outer tube and a concentric inner tube. The outer tube is perforated at selected locations by ports leading to gas tubes arranged lengthwise of the outer tube, but within the annulus between the inner and outer tubes. In each gas tube there is a thermocouple that is located at the perforation in the outer tube; each thermocouple being connected by a suitable signal conductor to an indicator. The probe is moved into and out of the furnace by means of a motor, and a vibrator is also provided to assist in moving the probe into the furnace.
How the present invention differs from the probe shown and described in U.S. Pat. No. 3,888,123 will become clear after reading the following detailed description of an embodiment of the present invention.
U.S. Pat. No. 3,240,069, referred to previously herein, also shows and describes a blast furnace probe that comprises an outer tube that is made up of cylindrical sections of varying diameters and tubular reducers. Thus, the tubular probe has a small diameter at the end entering the furnace and a relatively large diameter at the end outside the furnace wall, with stepped increasing diameter between the ends. A plurality of thermocouples are spaced along the length of the probe, and they are encased in tubular projections from the main stepped diameter tube. Associated with each tubular projection and the thermocouple, are gas ports in the projecting tubes through which gas samples enter a gas conduit leading to each projecting tube.
How the present invention differs from the blast furnace probe of U.S. Pat. No. 3,240,069 will become evident after reading the following detailed description of one embodiment of the present invention.